Means for measuring lengths of successive sheets of metallic material during rolling nd reduction of thickness of the same



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F. HUNT 3, MEANS FOR MEASURING LENGTHS OP SUCCESSIVE SHEETS OF METALLIC MATERIAL DURING ROLLING AND REDUCTION OF THICKNESS OF THE SAME Filed Oct. 6, 1960 2 Sheets-Shut 2 INVENTOR WILLIAM F. HUNT ATTQRNEY) United States Patent MEANS FOR MEASURING LENGTHS OF SUCCES- SIVE SHEETS OF METALLIC MATERIAL DUR- ING ROLLING AND REDUCTION OF THICKNESS OF THE SAME William F. Hunt, Louisville, Ky., assignor to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Filed Oct. 6, 1960, Ser. No. 60,972 2 Claims. (Cl. till-31.1)

This invention relates to an improved apparatus for use in rapidly producing a plurality of elongated sheets of metallic material having a standard thickness and length, and more particularly, to an apparatus wherein deviations from that standard thickness and length may be quickly recognized, to the end that corrective measures may be taken promptly.

In the rolling of continuous lengths of metallic sheets wherein a reduction in thickness of the sheet takes place during passage between the mill rolls, sufficient time is available for employment of conventional measuring means by which the draft being taken upon the sheet is determined and through the action of which measuring means a corrective control may be automatically exerted upon the rolling mill even while the sheet is still being rolled. Means of this type frequently embody a control based upon the ratio of the speed of the sheet emerging from the mill to the speed of that same sheet entering the mill. However, when discontinuous sheets, which may have a length in the order of only eight feet, are to be processed, a control of this nature is impractical, and, in general, when processing separate short sheets seriatim, it has heretofore been the practice to have a measurement taken manually on random rolled sheets by a separate operator who in turn advises the mill operator when sheets are found which deviate from the proper dimensions. In such an arrangement, many sheets may have been improperly processed before corrective measures can be taken, and in addition, the services of the separate operator are required. It is the purpose of the present invention to overcome these disadvantages.

This invention is especially useful in the fabrication of tube sheet panels formed from a multi-layer sheet of metallic stock material, such as aluminum, and initially having a thickness greater than, and a length less than, but with a width substantially equal to the respective thickness, length and width desired in the final panel. Such a sheet customarily is passed through one or more hot rolling steps and a subsequent cold rolling step in order to bring the sheet to the dimensions required in the panel, and with appropriate steps of heating, annealing, and the like being employed in conjunction with the rolling steps. As is apparent, the elongation of such a sheet during rolling is directly related to the reduction in thickness occurring during that rolling. Thus, upon measuring the rolled panel, which should have a standard length, any deviation from that standard length will indicate the necessity for correction in some phase of the fabrication procedure. Such factors as undue wear of the mill rolls or bearings, improper spacings of the rolls,

or the like, represent conditions which may require correction.

An object of the invention is to provide an improved means for measuring lengths of successive sheets of metallic material during rolling and reducing of thickness of such sheets.

Another object is to provide an improved combination of a rolling mill and a means for measuring the lengths of rolled sheets passing from that mill and actuated in dependence upon the working loading of the mill.

Other objects and advantages will become apparent as the description proceeds and when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of one arrangement for carrying out the invention in conjunction with a conventional rolling mill;

FIG. 2 is a side elevation view of an upper work roll for the mill showing in section one arrangement for actuating a switch in dependence upon the working loading of the mill;

FIG. 3 is a diagrammatic view showing one form of electrical circuit and one form of length-measuring means for use in connection with the invention; and

FIG. 4 is a diagrammatic view showing a second form of electrical circuit and a second form of length-measuring means for use in connection with the invention.

Referring first to FIGS. 1 and 2, a conventional rolling mill having a stationary massive frame 10 anchored in a foundation 11, is employed, it being understood that this invention in no way relates to the mill construction itself and that any of several commercially available mills may be used. As indicated, a hot rolling mill of the four-high roll stand type is illustrated and includes the usual lower backup roll 12, lower work roll 13, upper work roll 14, and upper backup roll 15. The lower backup roll and lower work roll are mounted in the usual relatively fixed bearings, respectively indicated generally at 16 and 17, one such bearing being provided at each end of each roll and supported in the frame. The upper work roll and upper backup roll are mounted in the usual adjustable bearings 18 and 19, respectively supported in the frame at each end of these vertically adjustable rolls. These adjustable rolls may be given a prescribed setting at each end by the usual roll adjusting screws, one being shown at 2.0, the screws being operated by screw down motors operated through reduction gearing as indicated respectively at 21 and 22. The work rolls 13 and 14 are driven from one end in the usual manner by a main mill drive motor, not shown, and as will be understood, these work rolls rotate continuously at a constant speed both during the idle loading and working loading of the mill.

As further indicated in FIG. 1, the usual feed and take off conveyors 30 and 31, respectively, are arrayed adjacent the mill so that an operator standing, for example, at the left side and upstream of the mill as shown, may guide an incoming sheet 32 of material passing along conveyor 30 into engagement with the work rolls, the rolled panel, as seen at 32A, then being passed outwardly along conveyor 31. In accordance with the invention, a length-measuring means indicated generally at 33 is arranged visually adjacent the mill rolls so that the operator at his normal station feeding the sheet into the mill may promptly observe the measured length of the preceding sheet which has passed on to conveyor 31. This measuring means, next to be described, is actuated in dependence upon the change from idle loading to working loading and from working loading to idle loading of the mill rolls, and it is comprehended by the invention that such changes may be manifested by any suitable arrangement of mechanical, electrical, hydraulic, or other means for so actuating the length-measuring device. For example, the power demand on the mill motor, stress on the roll bearings, strain on the rolls themselves, or displacement of the upper work roll itself may be employed as an actuating signal for the length-measuring device. The latter type of signal is particularly reliable, however, and is preferred and illustrated in the present disclosure.

One simple arrangement for providing the signal may include an elongated mechanical lever 35 pivoted at one end 36 to the downstream side of frame 10 and with its Patented Oct. 6, 1964 second end 37 disposed for free movement in a vertical plane adjacent the up-stream side of the frame. Intermediate its ends the lever carries a stub shaft 38 having a freely rotatable roller 39 mounted thereon as seen in FIG. 2. Adjacent its outer end and preferably opposite its drive end, the upper work roll 14 is provided with a peripheral groove 40 within which the roller 39 is constantly engaged. Due to the engagement of the sides of roller 39 with the side walls of the groove, the distal end of lever 35 is guided in a vertical plane and is prevented from shifting laterally, thus maintaining it in a path of movement intersecting the switch element now to be described. Moreover, the slight displacement of the upper working roll by the sheet of material is magnified by the leverage resulting from the roller being closer to the fulcrum 36 than the distal end of that lever, thus aifording a suflicient travel of the end 37 of the lever to insure a positive opening and closing of switch element 42.

Mounted upon the frame for engagement by the free end of the lever is any conventional adjustable switch means shown generally at 41 and having a movable switch element 42 arranged for contact with the free end of the lever during working loading of the upper work roll 14. Since the same mill may be employed for rolling sheets of different thicknesses and requiring commensurate adjustments in the screw down means, the switch means 41 is made adjustable and may include, for example, a fixed switch housing 43 mounted on the frame and having a conductor 44 of the electrical circuit for actuating the length-measuring means, connected thereto. The conductor 44 is interconnected to a source of electrical current (not shown) such as a generator, an electrical outlet or the like. This fixed housing may have an inclined surface facing and in contact with a companion movable switch housing 45 with a corresponding inclined surface and which housing 45 may be selectively moved thus to adjust the distance through which the end 37 of the lever travels before actuating the switch. The movable switch housing preferably carries the switch element 42 connected by a conductor 47 with the lengthmeasuring means 33, the switch element 42 when moved by the lever 35 making contact with a suitable terminal in the switch housing 43 to complete the circuit through the length-measuring means, and when separated from the lever 35, breaking contact with that terminal and interrupting that circuit. A suitable hand adjusting screw 48 mounted in a bracket 49 on the frame and rotatably engaging in supporting relation the movable switch housing 45 may be used to adjust the thus described switch means. Other equivalent and conventional switch means serving the same purpose may, of course, be employed without departing from the invention.

With the foregoing in mind, the operation of the apparatus may be noted in connection with the following description indicating two types of length-measuring means satisfactorily employed in carrying out the invention. Referring first to FIG. 3, a synchronous motor type of reset timer such as Model SW-l-ER manufactured by Meylan Stopwatch Corporation and having a large hand 60 revolving at one revolution per second and cooperating with an outer scale 61 marked in of a second, a small hand 62 cooperating with an inner scale 63 marked in seconds, and an adjustable pointer 64 adapted to retain a selected adjustable position, may be used. An electrical circuit including a conductor 44 leading to switch 41 and a conductor 47 leading to the timer motor and with a return lead 48, is employed in conjunction with a reset circuit for resetting the hands of the timer. The reset circuit includes a conventional switch 50 mounted in the path of movement of the sheets moving to the mill and biased to open position. As the leading edge of the sheet 32 contacts switch 50 a circuit is closed through conductors 51 and 52 to the solenoid within the timer, thus moving the hands 60 and 62 to zero position in readiness for the measuring operation. Preferably, a

supplementary manually operable switch 53 normally biased to open position is also furnished so that the timer may be reset at any chosen time.

Assuming now that the time required for moving a sheet 32 through the mill with the work rolls rotating at a constant speed and at a known setting to give a rolled panel 32A of a standard length and commensurate standard thickness has been determined, the operator accordingly adjusts the pointer 64 of the reset timer to a position indicative of that time required. The peripheral speed and size of the rolls 13 and 14 being known, it will be seen that the location of the pointer 64 then provides an indication of the desired length of the sheet and that the dial 61 may be calibrated in linear dimensions as well as time dimensions. He then feeds the sheet 32 upon conveyor 30 and as the leading edge of the sheet contacts switch 50 the hands 60 and 62 of the timer are automatically set to zero position. As the leading edge of sheet 32 enters between work rolls 13 and 14 initiating the working loading of the rolls, the sheet being of metal causes the upper work roll 14 to lift and at this time the roller 39 lifts and causes the lever 35 to pivot about its fixed fulcrum 36. The distal end of the lever then actuates the switch element 42 closing the circuit to the timer and causing the hands 60 and 62 to rotate. When, however, the trailing edge of the sheet 32 which now has been thinned to become the panel 32A, passes from the work rolls, reestablishing the idle loading of the rolls, the upper roll 14 promptly moves downward permitting roller 39 to move downwardly and lever 35 to pivot downwardly. At this instant, switch element 42 opens the circuit and the timer hands come to rest. The operator, without moving from his normal station, then observes the setting of large hand 60 with respect to the position of pointer 64 and can determine the length of the processed panel 32A which is the product of the peripheral speed of the work rolls and the time shown by hands of the timer. Since the scale 61 may be calibrated in hundredths of seconds, a range of a few hundredths on each side of pointer 64 normally signifies a range of time tolerance acceptable for differences in length of a commercially satisfactory panel. When, however, a series of consecutive panels each show a time of rolling falling outside this acceptable range, the operator then halts the rolling operation and makes the necessary corrections to overcome the discrepancy. It will be understood that in normal operation the panels are rolled in quick succession at a rate, for example, of about ten per minute for panels having a final length of six feet. By means of the invention, a skilled operator, without requiring the services of another operator, as heretofore has been the practice, can thus become immediately aware of any improperly processed panels.

As seen in FIG. 4 the invention may also be carried out with a length-measuring means of a different type and comprising a digital process controller such as Type Spec. 2016 manufactured by the Dynapar Corporation and including a rotopulser device 70 driven from the lower work roll 13 of the mill and converting angular motion of that roll into voltage pulses. By means of conductor 71 these pulses are fed into switch 41 and when the switch element 42 closes the circuit, are then fed through conductor 72 into a conventional controller having a direct reading numerical display section 73 and a recording section 74 showing the number of panels processed which are over, under, and of, the correct length, as well as the total number of panels processed.

As in the case of the arrangement in FIG. 3, the sheet 32 upon entering between the rolls causes the upper roll 14 to lift and through the roller 39 and lever 35 causes the switch 41 to close and the controller to function. Also, as the trailing edge of the panel leaves the rolls, the switch 41 opens as above described and the reading on the display section of the controller is extinguished. The operator, by observing that reading prior to its being extinguished, is made aware as to the length of the panel which has just passed through the mill and if a prescribed number of consecutive panels are too long or too short, may then shut down the operation of the mill and take the necessary corrective action. The invention is applicable to both hot and cold working mills and to mills which do not necessarily employ backup rolls.

Having thus described the invention and having shown alternative forms of length-measuring means for use therein, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the true spirit and scope of the invention. It is intended, therefore, that the foregoing disclosure is to be considered in an illustrative, rather than a limiting sense, and that the invention itself is to be considered as limited only by the scope of the appended claims.

What is claimed is:

1. In combination with a rolling mill for reducing the thickness of a succession of elongated sheets of metallic material fed seriatim thereto, said mill having a stationary frame, a lower roll mounted on said frame and rotatable on a fixed axis, an upper roll mounted on said frame and rotatable on an axis adjustable in a vertical direction, said rolls being adapted to be driven continuously at a constant speed during both the idle loading and working loading of the same; length-measuring means visually located adjacent said rolls for indicating the length of each sheet of material upon completion of its travel between said rolls, a normally open electrical circuit connected to said length measuring means for actuating the same, a switch in said circuit, and switch actuating means movable in dependence upon the raising and lowering of said upper roll thereby to close said circuit as said upper roll is lifted by engagement with the 6 leading end of said metallic sheet and to open said circuit as said upper roll is lowered by disengagement with the trailing end of said sheet, said length measuring means being actuated continuously during the time said upper roll is lifted and being calibrated to provide an indication of the length of said sheet as a product of the length of time said upper roll is liftedand the peripheral speed of said rolls, said switch actuating means comprising a lever pivotally mounted adjacent one end upon said frame, said lever having a second end adapted to open and to close said switch as said lever is respectively moved between first and second positions, and me'ansmounted onsaid lever intermediate the ends thereof and resting in engagement with said upper roll whereby said lever is moved to said second position as said upper roll is lifted and is moved to said first position as said upper roll is lowered.

2. Apparatus as defined in claim 1 wherein said upper roll includes a peripheral groove and said means mounted on said lever comprises a roller resting in said groove.

References Cited in the file of this patent UNITED STATES PATENTS Australia June is, 1956 

1. IN COMBINATION WITH A ROLLING MILL FOR REDUCING THE THICKNESS OF A SUCCESSION OF ELONGATED SHEETS OF METALLIC MATERIAL FED SERIATIM THERETO, SAID MILL HAVING A STATIONARY FRAME, A LOWER ROLL MOUNTED ON SAID FRAME AND ROTATABLE ON A FIXED AXIS, AN UPPER ROLL MOUNTED ON SAID FRAME AND ROTATABLE ON AN AXIS ADJUSTABLE IN A VERTICAL DIRECTION, SAID ROLLS BEING ADAPTED TO BE DRIVEN CONTINUOUSLY AT A CONSTANT SPEED DURING BOTH THE IDLE LOADING AND WORKING LOADING OF THE SAME; LENGTH-MEASURING MEANS VISUALLY LOCATED ADJACENT SAID ROLLS FOR INDICATING THE LENGTH OF EACH SHEET OF MATERIAL UPON COMPLETION OF ITS TRAVEL BETWEEN SAID ROLLS, A NORMALLY OPEN ELECTRICAL CIRCUIT CONNECTED TO SAID LENGTH MEASURING MEANS FOR ACTUATING THE SAME, A SWITCH IN SAID CIRCUIT, AND SWITCH ACTUATING MEANS MOVABLE IN DEPENDENCE UPON THE RAISING AND LOWERING OF SAID UPPER ROLL THEREBY TO CLOSE SAID CIRCUIT AS SAID UPPER ROLL IS LIFTED BY ENGAGEMENT WITH THE LEADING END OF SAID METALLIC SHEET AND TO OPEN SAID CIRCUIT AS SAID UPPER ROLL IS LOWERED BY DISENGAGEMENT WITH THE TRAILING END OF SAID SHEET, SAID LENGTH MEASURING MEANS BEING ACTUATED CONTINUOUSLY DURING THE TIME SAID UPPER 